TS ScalarQuery <TS>(DbManager db, Expression expr, object[] parameters)
{
var dispose = db == null;
if (db == null)
{
db = new DbManager();
}
try
{
var commands = SetCommand(db, expr, parameters, 0);
IDbDataParameter idparam = null;
if (SqlProvider.IsIdentityParameterRequired)
{
var sql = Queries[0].SqlQuery;
if (sql.QueryType == QueryType.Insert && sql.Set.WithIdentity)
{
var pname = DataProvider.Convert("IDENTITY_PARAMETER", ConvertType.NameToQueryParameter).ToString();
idparam = db.OutputParameter(pname, DbType.Decimal);
DataProvider.AttachParameter(db.Command, idparam);
}
}
if (commands.Length == 1)
{
var ret = db.ExecuteScalar <TS>();
return(idparam != null ? (TS)idparam.Value : ret);
}
db.ExecuteNonQuery();
return(db.SetCommand(commands[1]).ExecuteScalar <TS>());
}
finally
{
if (dispose)
{
db.Dispose();
}
}
}